Art of mixing concrete and other substances



Dec. 4,v 1934. H. o. STAMP V ART OF MIXING CONRETE AND .OTHER SUBSTANCES 5 Sheets-Sheet l` Filed Aug. 8, 1931 Dec. 4, 1934.

H. OfSTAMP ART 0F MIXING CONCRETE AND OTHER sUBsTANCEs Filed Aug. 8, 1951 5 Sheets-Sheet 2 Dec. 4, 1934. H. o. STAMP I ART OF MIXING CONCRETE AND OTHER SUBSTANCES Filed Aug. 8, 1951 3 sheets-sheet 3 Patented Dec. 4, 1934 PATENT Aori-letz ABT IWIXING CONCRETE AND OTHER `SUBSTANES i Hugo O. Stamp, Pittsburgh, Pa. Application August 8, 1931, Serial No. 555,987

,s claims.

This invention relates to the art of mixing concrete and other materials, particularly as carried out by means of transit mixers, and consists in the several-improvements to be hereinafter described and which are illustrated in the accompanying drawings. f

Figure A1 is a side elevation of 'a transit mixer Jembodying the improvements constituting the invention;

Figure 2 is a horizontal sectional view taken on the line II-II of Figure 1;

. Figure 3 is a longitudinal sectional view taken on the line III-III of Figure 2;

Figure 4 isa transverse sectional view taken ,1 5 on the line IV--IV 9i Figure 1; Figure `5 is a transverse'sectional view taken on the line V--V ofFigu're 2';

Figure 6 is a transverse sectional view taken on the line V'i--VI of Figure 2;

, Figure 7 is a detail sectional view taken on the line VII-VII of Flgure 3;

Figure!! is a vertical sectional view, of the rear end of the mixing drum and the adjacent adjustable mechanism` whereby the drum is locked 4' y25 against discharge until a' determined number of revolutions thereof for mixing purposes have taken place;

Figure. 9 is a sectional view taken on the line IX--IX of Figure 8; and J Figure 10 is a detail sectional view taken on the line X-X of Figure 9.

In the `drawings2 designates the chassis of a motor driventruck, including the running gear, power plant, drivers seat, steering mechanism ,65. and other usual parts ofsuch a machine. Driven from the motor of the truckthrough 'a transmission mechanism 3, which may be of any usual or preferred construction, is a power take-off shaft 4, connected with an intermediate shaft 'I through 4 9 suitablegearing, Dreferablysprocket gearing 8,

which intermediate shaft is connected, through other intermediate gearing 10 with the main shaft 9.' Upon this shaft is mounted a gear wheel 11 that is in driving mesh with-.a gear ring 12 exfternally supported upon a mixing drum 13. The

gear 11 is looselymountd uponthe shaft 9, with which-it may be connected at the will of the operator througha clutch 14, the movable element 15 of which is controlled by the driver ofthe vehicle,- through a shift handle 6 located near the drivers 1 .A clutch shifter shaft 16 is transversely supported on thechassis ofthe truck and is provided .with a yoke 17 having engagement withV the movi515 able element 15 ofthe-clutch. This shaft is provided with an arm 18 which is connected by a link or bar 19 with the handle 6 which has already been'referred to, the handle being an integral part of the bar or link 19 if desired. 20 indicates a brake drum which is connected with the gear 11 so as to turn therewith, and sur-` rounding such drum is a brake strap 21, one end of which is connected in any suitable manner with a xed attachment carried by the drum frame, the other end of the brake band being connected toa bell crank lever 22, which in turn is connected by link 23, with an arm 24 extending from the clutch shifter shaft 16. The arrangement of the parts just described is such that .the brake is applied simultaneously with the throwing out or disengagement o f the clutch 14 and will be released When the said clutch is thrown in, By the I'above construction the mixing drum may be rotated while the vehicle is proceeding on its Way to the place of use of the concrete which it is transporting; but, asis recognized, it is desirable to stop the drive of the drum when shifting gear for changing speed, and for this purpose an operative connection is provided between the ordinary gear shift lever 5 of the80 truck and the shift mechanism for the clutch 14 through which the drum is rotated. `This connection comprises a two part link or slide bar 25, connected at one end With the gear shiftlever t 5 and at its opposite end with a.- bell crank lever 85 26 which serves as a lock to prevent shifting of the transmission gears until the driving connection with the drum has been broken. The twov parts of the connecting link or bar 25 are united by a hinge 31so that the forward portion, which "'90 is connected to the gear shift lever 5, may swing therewith in horizontal directions while the usual gear shifting operations are being carried out. The rear portion of the bar or link 25, is formed. with a pair of projections or cams 27, 28, so located that between them is formed 4a notch or recess shaped to receive and properly fit one end, 29, of the locking `lever 26, which lever is suitably supported upon a bracket or 'other support carried by the framework of 100 the chassis. The other end of the lever 26, which is represented as so supported that it rocks in a horizontal plane, is forked or otherwise shaped to receive an end, 30, of the arm 24'projecting beyond the connection of the link 23 with such 105 arm, see Figures 3, 54 and?. With this construction, whenever the gear shift lever 5 is in a neutral position and the clutch 14 is engaged, the end 29 of the lever 26 seats in the notch or recess'between the. cams 2'1v and 28,;which pre- .110

vents movement of the bar or link 26, and hence the gears cannot be shifted. If, however, the clutch lever be shifted so as to disengage the connection between thepower shaft and the drumthe locking lever 26 will be disengaged from the link 25 and the gear shift lever 5 is free toV be operated. When the gear shift lever 5 is in its forward position, as represented by dotted lines in Figure 3, and the clutch 15 is at the same time engaged, connecting the drum for rotation, the end 29 of the bell crank lever 26 engages with the shift bar 25 just at the rear of the cam 27, so that a backward movement of the shift lever will cause said cam 27 to shift the locking lever 26 to the dotted line position represented in Figure 7, thereby throwing out the clutch and disengaging the mixing drum from the power shaft. In a similar manner, when the gear shift lever 5 is in its rear position and the clutch 14 is engaged, then the end 29 of the locking lever engages with the slide bar 25 just in front of the cam 28 so that a forward movement of the lever 5 to shift gears simultaneously causes the cam 28 to shift the locking lever 26 to the dotted line position of Figure 7. l'n each of these instances when the gear shift lever 5 comes to neutral position the lever 26 locks the bar 25 and the shift lever 5 against further movement until the clutch has been disengaged. In order that these movements may properly occur the clutch 14 is preferably of the type in which a spring acts to hold the movable element 15 thereof in operative position.

The drum 13 may be of any suitable or preferred shape, that shown being cylindrical in its rear portion and frusto-conical in its front part. Likewise any suitable means for mixing concrete when the drum is rotated may be employed, but no attempt has been made to illustrate such lmeans since they form no part of the present invention. Y

As represented, the drum is at its rear end formed with anextension and this extension, cooperating with the cylindrical rear portion of the drum from which a part has been removed, forms a discharge opening 33 which is provided with a door or closure 34, arranged to be held in place, closing the opening, by means of a locking bar 36. One end of this bar is formed into a hooi-1 37 adapted to engage with. a lug 33 carby the drum; while the other end 39, is shaped to nt into the slotted extension of an eccentric strap 40 mounted on an eccentric 41 which is carried by a shaft 42 supported in suitable bearings at the rear end. of the drum. The shaft 42 Ais provided with a handle for manual operation. When the handle is moved into the position indicated in full lines in Figures 9 and l0, the eccentric 41 is turned to the position shown in these views, and this in turn lifts the eccentric strap from the dotted line position of Figure 10 to the full line or locked position. This movement draws the door 34 into closed position, compressing the gasket 35 thereof, thus sealing the drum against discharge.

Provision is made for locking the door in closed position and maintaining it so locked until the drum has been given a certain number of revolutions. In the use of truck mixers it is common practice to require that the material .that is charged into the'drum shall be mixed a certain minimum amount before it shall be discharged for use. The means that are provided, according to the present invention, for thus insuring the desired amount of mixing will now be set forth, i

these being combined with the door closing means that have been described.

44 indicates a locking bar supported at the rear end of the drum by guides or keepers 76 in which the bar' is free to move. One end of this sliding locking bar is positioned so as to overlie the end of the handle 43 when the latter is moved into position to hold the door 34 closed over the opening 33, and the inner end carries a roller 45 that lies in a cam groove 46 formed in a disk 47 supported so as to ybe free to turn upon a sleeve or bearing 48 surrounding the shaft 50 of the drum, this sleeve 48, being preferably carried by a plate 49 secured fast to the rear end plate or wall of the drum.

The cam disk 47 is given a differential rotation with respect to that of the drum so that after a predetermined number of revolutions of the drum thecam groove 46 will move the bar 44 away from its locking position with respect to the handle 43. For providing the differential rotation of the cam disk the bearing 48, which turns with the drum, has secured fast to it, by key or otherwise, a sprocket wheel 5l. This is connected, by a sprocket chain 52 with a sprocket wheel 53 mounted upon a shaft 54 supported in the frame Work or support for the rear end of the shaft of the drum. A second sprocket 56 is supported upon the shaft 54, being either integral with the sprocket wheel 53 or so connected as to turn therewith, and this sprocket 56 is connected by chain 57 with a sprocket wheel 58 vmounted upon the shaft or sleeve 48, and free to turn upon the latter. The hub 59 of the sprocket wheel 58 is lengthened beyond the face of the wheel and has formed in its periphery a series of recesses 60 with any one of which a detent 6l may engage, see Figures 8 and 9. This detent is slidably mounted in a casing 62 carried by the cam disk 47. A spring 67 acting upon the detent tends to move it outwardly or to a position to free its end from a recess 60. A lock adaptedr to be operated by a key especially fitted' thereto serves to maintain the detent in4 its inner position, with the spring 67 under compression and the end of the detent in one of 'the recesses. it will be readily understood that a drum provided with mechanism such as has been .described when in rotation will cause the disk 47 to be turned, but with a different speed from that of the drum dependent upon the ratios of the gears 5l, 53, 56 and 58; and thus are provided means whereby the locking bar 44 may be moved to release the handle 43 after a certain number of revolutions of the drum have beenv completed. By making the disk 47 in which is formed the cam groove adjustable about its support it is possible to vary the number of revolutions that shall be given to the drum by setting the disk in one position j or another as will be apparent.

For any given batch of concrete to be mixed within the drum 13 it is desirable to know the wetness or dryness of the mix. I have found that after the clutch 14 has been thrown out the drum will reverse slightly before coming to rest and that the angle through which the drum swings back as the power is cut off, varies proportionately to the dryness of the mix. I therefore arrange a suitable angle scale 68 on the frame, preierably adjacent to the front end of the drum and place an arrow or other suitable indicator 69, on the drum to cooperate with the scale, and also provide mechanism for automatically throwing out the clutch in a given position of the the drum.

move therewith. The lever is formed with al trigger 72 hingedly connected thereto at its upper end and adapted to be inclined into a position in the path of a cam 73 on the drum, in which position it is held by the operator against the action of a'spring 74 While making a determination of the consistency of the mix. The trigger is ar- `ranged in a position to be manipulated by an ocapparatus and method employed for this purpose are adapted for use in connection with other operations than that of the making of a batch of concrete and wherein it is desirable to ascertain the consistency or character of the contents of the material which is being agitated in the revolving drum or container.

What is claimed is:

1. The herein describedmethod of determining the consistency of material being mixed within a revolving drum, which consists in effecting the mixing of the material by rotation of the drum, stopping the saidrotation of the drum and leaving it free to come to a position of repose upon its own axis and registering the reverse swing of/ the drum as it comes to repose.

2. The herein described method of determining the consistency of concrete, as to its relative wetness or dryness, which consists in mixing the same in a revolving container, and arresting the motion of the container when the mixing operation has been carried on to theI desired extent, leaving the container free to turn upon its own axis in response to eccentric loading due to the angle of repose of the material therein and measuring the reverse swing of the said container as it comes to rest.

3. The herein described method of determining the character of material being agitated within a revolving container-as to its settlement when agitation ceases- Which consists in eii'ecting th'e agitation of the material by rotation of the container, stopping the said rotation and leaving the material free to come to a position of repose, and the container free to swing upon its own axis, and registering the reverse swing of the container as it comes to such repose.

HUGO O. STAMP. 

